caa a22 4500 606202889 CHVBK 20210128100955.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s00429-014-0822-9 doi (NATIONALLICENCE)springer-10.1007/s00429-014-0822-9 Global versus tract-specific components of cerebral white matter integrity: relation to adult age and perceptual-motor speed [Elektronische Daten] [Micah Johnson, Michele Diaz, David Madden] Although age-related differences in white matter have been well documented, the degree to which regional, tract-specific effects can be distinguished from global, brain-general effects is not yet clear. Similarly, the manner in which global and regional differences in white matter integrity contribute to age-related differences in cognition has not been well established. To address these issues, we analyzed diffusion tensor imaging measures from 52 younger adults (18-28) and 64 older adults (60-85). We conducted principal component analysis on each diffusion measure, using data from eight individual tracts. Two components were observed for fractional anisotropy: the first comprised high loadings from the superior longitudinal fasciculi and corticospinal tracts, and the second comprised high loadings from the optic radiations. In contrast, variation in axial, radial, and mean diffusivities yielded a single-component solution in each case, with high loadings from most or all tracts. For fractional anisotropy, the complementary results of multiple components and variability in component loadings across tracts suggest regional variation. However, for the diffusivity indices, the single component with high loadings from most or all of the tracts suggests primarily global, brain-general variation. Further analyses indicated that age was a significant mediator of the relation between each component and perceptual-motor speed. These data suggest that individual differences in white matter integrity and their relation to age-related differences in perceptual-motor speed represent influences that are beyond the level of individual tracts, but the extent to which regional or global effects predominate may differ between anisotropy and diffusivity measures. Springer-Verlag Berlin Heidelberg, 2014 Aging nationallicence Diffusion tensor imaging nationallicence Fractional anisotropy nationallicence Cognition nationallicence Mediation nationallicence AC-PC : Anterior commissure-posterior commissure nationallicence AD : Axial diffusivity nationallicence CST : Corticospinal tract nationallicence DTI : Diffusion tensor imaging nationallicence DWI : Diffusion-weighted image nationallicence fSPGR : Fast spoiled gradient-echo imaging nationallicence FA : Fractional anisotropy nationallicence FMRIB : Functional MRI of the brain nationallicence FOV : Field of view nationallicence ICA : Independent component analysis nationallicence MD : Mean diffusivity nationallicence MNI : Montreal Neurological Institute nationallicence MR : Magnetic resonance nationallicence MRI : Magnetic resonance imaging nationallicence OR : Optic radiations nationallicence PCA : Principal component analysis nationallicence RD : Radial diffusivity nationallicence RF : Radio frequency nationallicence ROI : Region of interest nationallicence RT : Reaction time nationallicence SFNR : Signal fluctuation to noise ratio nationallicence SLF : Superior longitudinal fasciculus nationallicence SNR : Signal to noise ratio nationallicence TE : Echo time nationallicence TR : Repetition time nationallicence WAIS : Wechsler Adult Intelligence Scale nationallicence Johnson Micah Brain Imaging and Analysis Center, Duke University Medical Center, 27710, Durham, NC, USA aut Diaz Michele Brain Imaging and Analysis Center, Duke University Medical Center, 27710, Durham, NC, USA aut Madden David Brain Imaging and Analysis Center, Duke University Medical Center, 27710, Durham, NC, USA aut Brain Structure and Function Springer Berlin Heidelberg 220/5(2015-09-01), 2705-2720 1863-2653 220:5<2705 2015 220 429 https://doi.org/10.1007/s00429-014-0822-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00429-014-0822-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Johnson Micah Brain Imaging and Analysis Center, Duke University Medical Center, 27710, Durham, NC, USA aut NATIONALLICENCE 700 1- Diaz Michele Brain Imaging and Analysis Center, Duke University Medical Center, 27710, Durham, NC, USA aut NATIONALLICENCE 700 1- Madden David Brain Imaging and Analysis Center, Duke University Medical Center, 27710, Durham, NC, USA aut NATIONALLICENCE 773 0- Brain Structure and Function Springer Berlin Heidelberg 220/5(2015-09-01), 2705-2720 1863-2653 220:5<2705 2015 220 429